| 杨开林.冰盖河渠水深平均流速的横向分布[J].水利学报,2015,46(3): |
| 冰盖河渠水深平均流速的横向分布 |
| Lateral distribution of depth-averaged velocities in ice-covered channels |
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| DOI： |
| 中文关键词: 冰盖 河渠 水深平均流速 准二维 综合阻力系数 |
| 英文关键词: ice cover open channel depth-average velocity quasi-two dimension and composite friction factor |
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| 中文摘要: |
| 以Reynolds平均的Navier-Stokes紊流方程为基础，提出了冰盖河渠恒定流的水深平均流速的横向分布准二维模型，该模型包括了河渠流动的一些关键三维紊流因素，不仅适用均匀流和非均匀流，而且适用于明流和断面部分冰封的流动。建立了综合阻力系数fd 与河床糙率系数nb 和冰盖糙率系数ni 的函数关系， 其中nb 和ni 可以是常数，也可以是横坐标y 的函数。典型冰盖梯形明渠的算例表明，本文模型具有足够的计算精度，同时计算明流无因次涡流黏度λ 的方法也适用于冰盖下流动。 |
| 英文摘要: |
| Based on the Reynolds averaged Navier-Stokes equations，a quasi-two dimensional model is presented to determine the lateral distribution of the depth-averaged velocities in steady flows in ice-covered channels. The model， including some key factors on the three dimensional turbulent flows， can be used to simulate not only the steady uniform flows and non-uniform flows，but also free flows and partially-covered flows. For the composite friction factor fd， a formula is establishes that is involved in the lateral ordinate y， the local riverbed roughness coefficient nb and local ice cover roughness coefficient ni. At last， several typical examples are given. The results illustrate that the model presented herein is satisfactory in accuracy，and that the formula for the dimensionless eddy viscosity in free flows in open channels is also applicable to the flows under ice cover. |
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